A power semiconductor device such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an IGBT (Insulated Gate Bipolar Transistor) has high-speed switching characteristics and a breakdown voltage of tens to hundreds of volt, and is widely used for electric power conversion and control in a home electric appliance, communication equipment, an in-car motor, and the like. Then, for improving efficiency and reducing power consumption in such equipment, the semiconductor device is being required to have characteristics of the high breakdown voltage and a low on-resistance. For example, in a semiconductor device that includes a super junction structure in which a p-type and n-type semiconductor layers are arranged alternately, it is possible to obtain both characteristics of the high breakdown voltage and the low on-resistance.
However, when a larger bias is applied to the super junction structure, there arises a problem in which p-n junction capacitance is abruptly reduced and the output capacitance of the semiconductor device is considerably changed. That is, the semiconductor device that includes the super junction structure has a large switching noise depending on the output capacitance. Accordingly, it is necessary to realize a semiconductor device that includes a super junction structure in which the output capacitance is increased to reduce the switching noise.